Bradley Cooper and Elizabeth Olsen to Join Marvel Universe?

There are big developments in the Marvel universe this week, with Bradley Cooper and Elizabeth Olsen reportedly up for parts in two of the studio's upcoming tentpoles.

According to sources for The Hollywood Reporter, Cooper is in negotiations to voice Rocket Raccoon in "Guardians of the Galaxy." The talks are in the early stages, but THR says Cooper would be playing the CGI character, described as "a genetically engineered animal with a knack for guns and explosives."

Also in talks to play a CGI addition to the gang is Vin Diesel, who's up for the part of tree-man hybrid Groot. Shooting has already started on the star-studded film, set to open August 1, 2014.

Olsen, meanwhile, is a strong possibility for the role of Scarlet Witch in "The Avengers: Age of Ultron," the hotly anticipated 2015 sequel to smash hit "The Avengers." THR reports that Olsen's negotiations are in the advanced stages.

Scarlet Witch is endowed with the power to alter probabilities, and she also has a twin brother, Quicksilver. The spawn of mutant "X-Men" villain Magneto, the pair made their Marvel debut as bad guys before joining forces with the Avengers.

Both casting additions would be coups for the studio. Cooper is coming off a hot year with his Oscar-nominated turn in "Silver Linings Playbook," and seems to be up for a repeat in "Silver Linings" director David O. Russell's upcoming "American Hustle." Olsen has been making the transition from indie darling to blockbuster leading lady, and could add some heft to the superhero flick. Look for both to make a big splash should they secure the parts.